A Clearer Picture of Atherosclerosis

Magnetic resonance images of the cardiovascular system offer a surprising view of how early atherosclerosis starts.

The hardening and narrowing of the arteries brought on by the buildup of fatty plaques (atherosclerosis) develops over time. So it may be many years before patients notice the symptoms of cardiovascular disease (CVD) atherosclerosis can cause.

Atherosclerosis affects the vascular “tree,” throughout the entire body. However, current imaging methods allow doctors to look at only the arteries in small segments of the cardiovascular system at one time. This can mean that doctors can miss early-stage atherosclerosis and a valuable opportunity for early intervention, which can slow or prevent the progression of CVD.

Researchers were surprised to find that nearly half of people in the low-risk study population had at least one blood vessel narrowed by atherosclerosis.

Whole-body magnetic resonance (MR) angiography is a technique that gives doctors a way of surveying the entire vascular system for the presence of cardiovascular disease. The technique has led to a concerning discovery: A study using MR angiography has found that in many cases, people thought to be at low to intermediate risk of CVD have signs of atherosclerosis.

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This discovery brings a benefit, according to Graeme Houston, a co-author of the study and a professor in the divisions of molecular and clinical medicine at the University of Dundee in Scotland. MR angiography could help doctors better identify persons with early-stage atherosclerosis, leading to more effective use of preventive treatment.

Over 1500 people were examined for atherosclerosis using whole-body magnetic resonance angiography. All of the people in the study were believed to have less than a 20 percent risk for developing CVD over the next 10 years. The researchers examined 31 segments of the vascular system in each participant.

As they expected, the amount of atherosclerosis in each person corresponded to his or her age, blood pressure and cholesterol levels, all known risk factors for cardiovascular events such as heart attacks. But the researchers were surprised to find that nearly half of people in the low-risk study population had at least one blood vessel narrowed by atherosclerosis, and 27 percent had multiple blood vessels affected by it.

Magnetic resonance angiography is far more accurate than the invasive angiography that is currently used. The researchers were able to interpret 99.4 percent of the potentially analyzable arterial segments using whole-body MR angiography. Houston believes the technique’s high success rate and accuracy suggests potential for expanding early detection and treatment.